A few more details (archive)

As is suggested by the chart, it required a tedious 19 number of dyno runs to develop and optimize the software code for an 850CSi equipped with extrude-honed intake manifolds and a Supersprint exhaust. The 20th run was to compare the Dinan chips after we were finished. We're talking about first doing base runs, then optimizing fuel curves with multiple runs, and then optimizing ignition timing with multiple runs. And then confirming no further gains were possible. Jim probably spent the better part of nearly three hours going through this process and those of us who were there witnessed it all.

The most important lesson learned at the dyno session was that use of extrude-honed intake manifolds on a 12 cyl. engine offer substantial and verifiable performance gains. At least in the case of 850CSi's, the car so equipped was putting out more power and torque at the lower and upper rpm ranges WITHOUT Jim C. tuning than the non-extrude honed intake 850CSi AFTER Jim C. tuning. With the addition of Jim C. tuning, the extrude honed equipped car surpassed through the entire rpm band. As I've mentioned before, the gains he obtained on the 6-speed 850i's were huge, and I imagine that a 6-speed 850i with Jim C. chips and extrude honed intakes would be even more so.

Whether you have an 850i or 850CSi, what makes these cars so pleasurable to drive is the torque. Study the torque curves, and you'll understand why we're all driving around with grins on our faces.

Follow Ups:

[ Follow Ups ] [ 8-series (E31) Message Board ] [ Msg. Board FAQ ]

Questions, comments, or problems, please visit the Roadfly help desk.